1. Field
An anti-Ang2 antibody or an antigen-binding fragment thereof that specifically binds to an angiogenesis-inducing factor Angiopoietin-2 (Ang2) and complexes with a Tie2 receptor through Ang2, and methods of using the same, are provided.
2. Description of the Related Art
Angiogenesis refers to a mechanism through which a new blood vessel is formed from a pre-existing blood vessel, and has been known to play an important role in, e.g., the formation of organs, promoting normal physiological growth, promoting wound healing and the like. Abnormal angiogenesis has been known to play a crucial role in diseases such as tumor growth and metastasis, age-related macular degeneration, diabetic retinopathy, psoriasis, rheumatoid arthritis, and chronic inflammation.
Angiogenesis has been known to play an important role in tumor growth and metastasis, and various intensive researches on angiogenesis mechanism for developing a new cancer drug have been going on by developed countries and multinational pharmaceutical companies. One of the proteins that have been the target of research is Angiopoietin which has been known to be involved in blood vessel development and angiogenesis after birth. Known members of the angiopoietin family include Ang-1, 2, 3 and 4.
Angiogenesis related to Angiopoietin-2 (Ang2) in a cancer tissue is believed to occur as follows. First, for angiogenesis in the cancer tissue, cooption wherein cancer cells select pre-existing blood vessels to form new blood vessels in a cancer tissue occurs. Thereafter, blood vessel regression during which the functions of the pre-existing blood vessels are destroyed by Ang2 pathway occurs. The regression of the pre-existing vessels causes hypoxic environment within the cancer tissue, which is an environment where the formation of new blood vessels is possible. Under such conditions, the expression of vascular endothelial cell growth factor (VEGF) is increased, and new blood vessels are thus formed.
Thus, Ang2 is of increasing importance as a target for developing an angiogenesis inhibitor, and there is a need of developing an effective and strong Ang2 targeting substance.